A novel cellular pychopharmacological monitoring system was developed (patent pending) for research in freely moving animals. The system is built around a miniature air-controlled minivalve. This device can be placed on the head of the animal and is able to drive either a control solution or a drug solution into the brain via a microelectrode-coupled microdiaysis probe. The short distance between the minivalve and the microelectrode/microdialysis probe unit allows to deliver drugs into the brain rapidly and to record the drug-induced cellular electrophysiological changes instantly. The minivalve is activated remotely by air with a controller. The control solution, the drug solution, the waste fluids, the microdialysis fluids, and the air that activates the minivalvel pass through a 8-channel swivel. This swivel is connected to a 18-channel electrical commutator. The swivel/commutator unit is rotated by a torque-sensitive servo driver and is connected to the minivalve and the microelectrode/microdialysis probe unit via a special cable. The system is completed with an electrical signal distributor to make the electrophysiological data acquisition convenient. The entire monitoring system, that includes the minivalve, the minivalve-controller, the servo- rotated swivel/commutator unit, the special cable, and the electrical signal distributor will be available in 2001 as a single, easily usable package, at a price of approximately $13,000. The minivalve can be carried by rats, mice, and larger animals on their head, without disturbing their behavior. Since this system enables the investigator to quickly test the cellular electrophysiological effects of many drugs in brain in natural circumstances during behavior, the technology opens up new possibilities for studying drug actions in the central nervous system. As such, the developed system will likely be widely used in the academia and the pharmaceutical industry. PROPOSED COMMERCIAL APPLICATION: 1. In the academia, neuropharmacologists and psychopharmacologists can use the minivalve-system to map the in vivo cellular electrophysiological effects of various well-established drugs, such as sedatives, antidepressants, cognition enhancers, antiepileptics, etc., in the brain of both normal animals and animal models of CNS disorders. 2. Also in the academia, cell biologists, molecular biologists and pharmacologists can use the minivalve system to obtain new information on the role of various neurotransmitters, ion channels, second messengers and genes in the regulation of neuronal electrical activity in the animal brain, during such behaviors as learning, sleep, eating, drinking, sex, etc. 3. In the pharmaceutical industry, researchers can use the minivalve- system to document how their company s new compounds act on the neurons of the animal brain, in vivo. 4. Also in the pharmaceutical industry, researchers can use the minivalve- system to recognize the beneficial cellular electrophysiological effects of their experimental compounds on the electrical activity of neurons in the animal brain, in vivo.